Submission #1123507

#	Time	Username	Problem	Language	Result	Execution time	Memory
1123507		imarn	Airplane (NOI23_airplane)	C++20	0 / 100	115 ms	19108 KiB

Main

#include<bits/stdc++.h>
#define ll long long
#define pii pair<int,int>
#define pll pair<ll,ll>
#define plx pair<ll,int>
#define f first
#define s second
#define pb push_back
#define all(x) x.begin(),x.end()
#define szz(r) (ll)r.size()
#define vi vector<int>
#define vvi vector<vi>
#define pp pair<ll,int>
#define ub(x,i) upper_bound(all(x),i)-x.begin()
using namespace std;
const int mxn=2e5+5;
vector<int>g[mxn];
int a[mxn];
ll dst[2][mxn]{0};
bool vis[mxn]{0};
void solve(int u,int x,int n){
    vector<pii>vec;
    for(int i=1;i<=n;i++)vec.pb({a[i],i});
    sort(all(vec));
    int mem=vec[0].f;
    priority_queue<pii,vector<pii>,greater<pii>>pq;
    for(int i=1;i<=n;i++)dst[x][i]=2e16;dst[x][u]=0;
    for(int i=0;i<vec.size();i++){
        //cout<<vec[i].f<<' '<<vec[i].s<<' '<<dst[x][vec[i].s]<<'\n';
        if(mem==vec[i].f&&dst[x][vec[i].s]!=2e16){
            int v=vec[i].s;pq.push({dst[x][v],v});
        }
        else if(vec[i].f!=mem){
            //cout<<mem<<' ';
            while(!pq.empty()){
                auto uu=pq.top();pq.pop();
                //cout<<uu.s<<' ';
                if(vis[uu.s])continue;
                vis[uu.s]=1;
                for(auto v:g[uu.s]){
                    if(dst[x][v]>max(a[v],uu.f+1)){
                        dst[x][v]=max(a[v],uu.f+1);
                        if(a[v]<=mem)pq.push({dst[x][v],v});
                    }
                }
            }mem=vec[i].f;int v=vec[i].s;
            if(dst[x][v]!=2e16)pq.push({dst[x][v],v});
            //cout<<'\n';
        }
    }//cout<<mem<<' ';
    while(!pq.empty()){
        auto uu=pq.top();pq.pop();
        //cout<<uu.s<<' ';
        if(vis[uu.s])continue;
        vis[uu.s]=1;
        for(auto v:g[uu.s]){
            if(dst[x][v]>max(a[v],uu.f+1)){
                dst[x][v]=max(a[v],uu.f+1);
                if(a[v]<=mem)pq.push({dst[x][v],v});
            }
        }
    }
    memset(vis,0,sizeof vis);
}
int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);
    int n,m;cin>>n>>m;
    for(int i=1;i<=n;i++)cin>>a[i];
    for(int i=1;i<=m;i++){
        int x,y;cin>>x>>y;g[x].pb(y);g[y].pb(x);
    }
    solve(1,0,n);
    solve(n,1,n);
    ll rs=2e16;
    for(int i=2;i<=n-1;i++)rs=min(rs,dst[0][i]+dst[1][i]);
    cout<<rs;
}

• Subtask 1: 0 / 22
• Subtask 2: 0 / 10
• Subtask 3: 0 / 31
• Subtask 4: 0 / 37